1. Field of the Invention
This invention is related to a method and apparatus for supporting a mine opening and, more particularly, to a pumpable crib and a method for installing a pumpable crib used to support a mine opening.
2. Description of Related Art
Cribbing is frequently used to provide support in underground mine openings. Wooden cribbing formed from stacked pieces of timber generally allows for large amounts of vertical displacement prior to failure. Pumpable cribs, which are formed by pumping a cementitious material into a collapsible containment bag, generally withstand much larger loads than wooden cribbing, but do not allow for as much vertical displacement as the wooden cribbing prior to failure. The containment bags are typically textile or fabric bags made of polypropylene and/or polyethylene, which are secured to a roof of the mine opening. The containment bags usually have a tube and one-way valve for receiving the cementitious material under pressure.